MASS migration to Britain has pushed birthrates in parts of the UK to among the highest in Europe.

Official figures show Uk gained an extra 400,000 people from 2012 to 2013 [STOCKBYTE/GETTY]

A migrant baby boom and large-scale immigration mean poverty-stricken former mill towns in northern England are some of the most fertile and youngest in the EU, according to official figures.

The unemployment blackspot of Blackburn in Lancashire is now effectively the most youthful town in Europe thanks to babies born to foreign mothers and immigrant children.

It has long been known that migrant women have higher birth rates than British and are bringing young children with them to the UK.

This latest data graphically illustrates the strain migration is putting public services - especially schools and hospitals - in some of the country's poorest areas.

The statistics also show how uncontrolled migration is changing the face of Britain's former industrial heartlands.

Recent ONS data showed that mass migration sent Britain's population soaring above 64 million for the first time, with the country gaining an extra 400,000 people from 2012 to 2013.

These statistics show yet again the economic price the people of Britain are paying for the failure of successive governments to address uncontrolled mass immigration into Britain

Steven Woolfe, Euro MP for Blackburn and Ukip migration spokesman

The population has grown twice as fast as the rest of Europe over the past decade, gaining as many people in that time as in the entire previous generation.

Sir Andrew Green, the chairman of Migration Watch UK, which campaigns for low immigration, said: "This is yet another example of the impact of mass immigration on our society."

Steven Woolfe, Euro MP for Blackburn and Ukip migration spokesman said: "These statistics show yet again the economic price the people of Britain are paying for the failure of successive governments to address uncontrolled mass immigration into Britain.

"Since 1997, ov­­er 4 million people have settled in the UK. Mass immigration at this level is simply unsustainable. Unpredictable birth rates and population growth make it impossible to effectively plan, finance and manage future public services and mean a poorer provision for everyone."

Figures, published this week by Eurostat - the EU's statistical wing - showed Blackburn and Darwen district was the top area for under-15s, with almost one in four - 22.2 per cent - of its residents under that age in 2013.